1. Field of the Invention
The present invention relates to a view finder display device having a liquid crystal cell for displaying photographic information and various kinds of alarms.
2. Description of the Prior Art
Conventional devices for displaying photographic data involve meters that incorporate D'Arsonval type moving-coil galvanometer arrangements. Such meters have a number of disadvantages such as susceptibility to disabling shocks and the high cost of miniaturizing these devices. Furthermore, the openings which permit the meter needle to project into the view field of a camera fiew finder, so that they can be seen while focusing, allow dust to enter the view finder. Moreover, the meter needle is sometimes difficult to see. As a further point, a photographer may become confused and fail to notice the needle when the needle moves into the red warning or limit zones that are frequently provided in the upper and lower ends of such view finders. It is possible to move warning members into and out of the visual field for purposes such as indicating a low battery voltage, but this makes the entire device rather complicated. Light emitting diodes (LEDs) may be used as limit indicators or warnings, but these consume considerable power.
Needless to say, the substitution of light emitting diodes for a moving coil meter would result in prohibitive power consumption. The act of checking the battery with such indicators would itself drain the battery unnecessarily.
In some viewfinders, the meter needle which displays photographic values such as the measured light, is also used to indicate the voltage during a battery check. The use of this single needle for multiple purposes may confuse the photographer.
Aside from these disadvantages, the projection of the meter needle into the viewfinder may adversely affect the operator's ability to compose a picture. On the other hand, if the needle does not project into the viewing frame, a photographer may not notice an alarm indication.
As a result, conventional viewfinders may become complicated and unnecessarily costly.
Liquid crystal devices of the type that have been used as displays require either high voltages or have been difficult to read.
An object of the invention is to improve viewfinder displays for cameras.
Another object of the invention is to avoid the aforementioned shortcomings.